Americana heroes The Avett Brothers return to the Three Rivers Arts Festival

Their banjo-driven Americana bubbles sweet and earnest, spiced with wit and wisdom. Backed by upright bassist Bob Crawford, the honeyed harmonies of brothers Scott and Seth Avett drip down the sides of gently shuffling melodies.

The Avett Brothers' dusty traditionalism dovetails nicely with their openhearted writing, which tends to strip back our daily illusions. Disabusing us of our soundstage dreams on "Love Like the Movies," they warn, "With a twinkle in their eyes / They're just saying their lines," noting "real life is more than two hours long." On "The Weight of Lies," off their most recent album, Emotionalism, the chorus counsels, "When you run, make sure you run / To something and not away from."

Their live performances attain a high-spirited, near punk-rock intensity which has helped cement a strong grassroots following bordering on underground sensation. Though the acoustic instrumentation tends to dictate a country-folk tone, energetic tracks like "Talk on Indolence," veer toward '50s rock 'n' roll, while Emotionalism tightens the bolts of their pop sensibility, refining their shambling pulse toward a touch of wry elegance, as on the cabaret-tinged "Paranoia in B Major."

"It's much more of a smorgasbord or melting pot of all the places we've come from," says Scott Avett, describing their latest album.

The Avetts were originally part of a five-piece rock band in Greenville, N.C., named Nemo, but were writing different music together on the side. Nemo imploded in 2000, allowing the new sound to take precedence.

"We were getting more serious about it. We'd really been busking a lot. Playing anywhere we could at any time," says Scott, citing Gillian Welch and David Rawlings as big influences. Feeling something still missing, they invited New Jersey native Crawford to join up in 2002, prior to their second album, Country Was. Since then, they've maintained a prolific pace, releasing five studio albums, a handful of live albums and EPs. Things started to really pick up for them after their 2005 Merlefest appearance netted them Best New Artist honors, and have accelerated ever since.

Next on tap is a six-song EP titled The Second Gleam (following 2006's Gleam EP), which comes out in July. As they continue to expand their roots palette, Scott admits there's a limit to their experimentation. "It can become predictable when you're always trying not to be predictable," he says. "That's an Avett recipe."

The Avett Brothers with Good Brother Earl. 6:30 p.m. Sat., June 21. Three Rivers Arts Festival Main Stage, Stanwix Street at Liberty Avenue, Downtown. Free. All ages. 412-281-8723 or www.artsfestival.net